1. Industrial Field of the Invention
The present invention relates to a cover opening/closing device in an apparatus having a cover which is opened/closed when rotated about a rotational shaft provided in a main body, e.g., a cassette cover of a cassette tape recorder or the like.
2. Description of the Prior Art
Recently, various kinds of devices have been suggested as a cover opening/closing device in an apparatus with a cover which is opened/closed when rotated about a rotational shaft provided in a main body, such as a cassette cover of a cassette tape recorder or the like. One example of the conventional cover opening/closing device will now be described with reference to the attached drawings.
FIG. 11 is a front view showing one example of a cover opening/closing device in a conventional cassette tape recorder, and FIG. 12 is a cross-sectional view of the same in the cover-closed state. Referring to these figures, a cover 31 serving as a cassette envelope is designed to open and close a main body 32, and an engaging piece 33 for closing the cover is attached on a free-end portion of the cover 31. A chassis 34 is provided in the main body 32. A cover opening lever 35 is integrally formed with an engaging claw 36. An open knob 35a is formed on the cover opening lever 35. A spring 37 for returning the cover opening lever 35 is interposed in such a manner that one end of the return spring 37 abuts against the cover opening lever 35, and that the other end abuts against the chassis 34. In the illustration, reference numeral 38 denotes a tape cassette received in a receiving portion on a mechanism chassis 39 which is provided inside of the main body 32.
With such a structure, in order to open the cover, the cover opening lever 35 is operated in the compression direction (indicated by the arrow in the illustration) against the urging force of the return spring 37, to thereby release the engaging claw 36 from the engagement with the engaging piece 33 of the cover 31. Thus, the cover is opened by the urging force (not shown) in the cover opening direction which is applied to the cover 31, or by manual operation. On the other hand, in order to close the cover, the cover 31 in the open state is pressed and urged toward the main body 32, so as to bring the engaging piece 33 into contact with the engaging claw 36 of the cover opening lever 35. By further pressing and urging the cover 31, the cover opening lever 35 is operated in the compression direction of the return spring 37. When the engaging piece 33 reaches the position where it is engaged with the engaging claw 36, as shown in FIG. 11, the cover opening lever 35 is engaged by the return force of the return spring 37.
In the conventional cover opening/closing device described above, a gap a is defined between the cover 31 and the main body 32 so that return of the return spring 37 will not be interrupted, in order to surely hold the position of the cover opening lever 35 at the time of cover closing operation. However, the gap a cannot be kept constant due to deviations of the finished dimensions of component parts and so forth, thereby deteriorating the quality as a product. Further, deviations in the gap a, the thickness of the tape cassette 38 received in the main body and so forth result in another problem that the tape cassette 38 may freely move inside of the main body, as indicated by dotted lines in FIG. 12, and cannot be held therein stably.
Taking the problems of the conventional technique into consideration, this invention has been achieved to attain an object to provide a cover opening/closing device which minimizes backlash between the cover and the main body when the cover is closed, and which enables an article to be received between the cover and the main body stably.